Derek Adams cut a frustrated figure as he reflected on the game.

He is not the first opposition manager to be left feeling that for the most part, there wasn't a lot between his side and Sunderland.

Dylan McGeouch was effective again for Sunderland as they kept a fourth consecutive clean sheet

He was also the latest manager to be on the losing side.

Adams praised the 'magnificent' Jon McLaughlin and said that his team-mates and staff should be thanking him for his efforts.

That praise was genuine but equally clear was the inference: Sunderland had been bailed out by their goalkeeper.

Like Doncaster Rovers and countless others, Plymouth were left ruing the vital moments that went in Sunderland's favour.

Here, it was a pair of superb saves from the Scotland international that prevented the home side drawing level midway through the second half.

A tight penalty call then settled the contest and so Plymouth's efforts were in vain. Though they tested the away side with their pace and width, the Black Cats sealed their fifth league win on the bounce.

Adams pointed to the stats that showed Plymouth had far more attempts on goal.

So are Sunderland fortunate that despite not always being dominant in games, they are winning regularly, keeping clean sheets and building the best goal difference in the league?

Not in the slightest.

Football games are won in both boxes and there Sunderland's quality is making the difference.

In the early part of the season it was Josh Maja who was elevating Sunderland, showing a ruthless streak that settled tight contests.

Niggling injuries have slightly curtailed his progress but in his place, others are stepping up.

Aiden McGeady's opening goal was a classic example of that. Adams said that even in the first half, he felt there were spaces between midfield and defence for both sides to potentially exploit.

McGeady did it ruthlessly, a run and finish of the highest quality.

It underlined just how clinical this team are in front of the opposition goal.

At the other end, Sunderland have made what is, at this stage, surely the best signing of any side in the league this season.

A settled defence has limited the chances opposition teams are carving out but even in the inevitable moments when they do threaten, Sunderland have a stopper who is the equivalent of a 20-goal striker.

It's no fluke. Jack Ross knew Jon McLaughlin was this good and that is why he was one of his first signings for the club.

In midfield, Sunderland have players who combine intelligence and industry.

This was Dylan McGeouch's best performance in a Sunderland shirt, vital interventions in his own box are becoming a feature in this winning run. George Honeyman broke the play up well and particularly away from home, that is the platform allowing the individual quality of their team-mates in the final third to shine through.

Last season, there were a whole host of games where Sunderland were desperately poor. But there were also plenty where from box to box, they competed reasonably well. The problem was that they couldn't take their chances in one and were gifting goals away in the other.

At the Stadium of Light this season, they have played open, expansive, attacking football.

Away from home it has not been so easy but Jack Ross was right to say that other than a 15/20 minute period in the second half, they were not overly stretched.

It was a professional, controlled win.

Another one.

Sunderland's opponents can justifiably take the positives from their performances but it shouldn't detract from what Jack Ross and his side are doing.

That they've fought their way into the automatic promotion places is no fluke, and don't bet against them making it a prolonged stay.